HS5.9 | Impacts of land use and land cover changes on water resources and water-related ecosystem services: from assessments to solutions
EDI
Impacts of land use and land cover changes on water resources and water-related ecosystem services: from assessments to solutions
Convener: Giulio Castelli | Co-conveners: Sofie te Wierik, Tommaso Pacetti
Orals
| Wed, 26 Apr, 10:45–12:30 (CEST)
 
Room 2.31
Posters on site
| Attendance Wed, 26 Apr, 16:15–18:00 (CEST)
 
Hall A
Posters virtual
| Attendance Wed, 26 Apr, 16:15–18:00 (CEST)
 
vHall HS
Orals |
Wed, 10:45
Wed, 16:15
Wed, 16:15
Land use and land cover (LULC) changes are one of the main drivers of change to hydrological processes, altering the ecosystem dynamics and impacting the production of water-related ecosystem services (WES) with different levels of societal impact. These LULC changes can emerge directly from anthropogenic interventions, or indirectly as the result of climate change. There is an extensive body of research investigating the impact of LULC changes on streamflow dynamics, but less so on other elements of the hydrological cycle (e.g. groundwater quantity and quality, evaporation and transpiration, soil moisture and rainfall interception) and associated ecosystem services. Changes to these elements can possibly lead to non-local and non-linear effects on ecosystem services, which need to be understood to inform effective and equitable water resource management.

This session welcomes studies that address the impacts of LULC changes on all water resources and hydrological processes, and associated WES, such as flood regulation, moisture recycling, temperature regulation, and food provisioning. Furthermore, beyond impact assessments, we welcome scholars that address policy options to mitigate harmful impacts on WES. More specifically, we welcome studies including, but not limited to:

• Advances in the quantification of hydrological impacts of LULC changes through modelling and experimental data, including water quantity and quality
• Disentanglement of LULC change impacts on all water resources (blue surface and groundwater, green water, atmospheric water) and associated WES
• Analysis and evaluation of policy interventions to mitigate impacts, such as ecological restoration schemes and nature-based solutions, with respect to their effectiveness and feasibility to protect and/or restore WES
• Advances in (interdisciplinary) methodologies for identifying WES, as well as studies highlighting spatial assessments of WES

Orals: Wed, 26 Apr | Room 2.31

Chairpersons: Giulio Castelli, Sofie te Wierik, Tommaso Pacetti
10:45–10:50
10:50–11:10
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EGU23-17370
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solicited
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Highlight
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On-site presentation
Stefan Uhlenbrook, Sulagna Mishra, Luis Roberto Silva Vara, Johanna Korhonen, Washington Otieno, and Hwirin Kim

Societies, economies and ecosystems depend on sustainable and resilient hydrological services provided by in-tact hydrological systems and processes. These services are defined by the inter-dependencies of various drivers of which land use and land cover changes (LULC) as well as climate change are increasingly dominating, often leading to degraded hydrological services and altered ecosystem dynamics with different levels of societal and economic impacts.

Increasing and more frequent hydrological extremes (floods and droughts) and reduced water availability for various users and uses, often accompanied with increasing water demands, require effective operational water management. Therefore, in-depth knowledge of hydrological processes and their links to LULC, climate changes and other human interventions as well as tools are required to guide water management and policy decisions, such as, increasing water storage in grey and/or green infrastructure, caps on water consumption, or ecosystem restoration. This presentation reviews key processes and introduces the Hydrological Status and Outlook System (HydroSOS) and related assessment and reporting approaches to inform decision and policy-making. Therefore, a scale-specific approach is suggested in which LULC, water use and hydrological processes are embedded in a larger systems approach (including natural and human systems) to guide operational management and policies.

How to cite: Uhlenbrook, S., Mishra, S., Silva Vara, L. R., Korhonen, J., Otieno, W., and Kim, H.: Supporting operational water management and policy making through scale-specific approaches, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17370, https://doi.org/10.5194/egusphere-egu23-17370, 2023.

11:10–11:20
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EGU23-2627
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ECS
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Virtual presentation
Muhammad Haris Ali, Ioana Popescu, Andreja Jonoski, and Dimitri Solomatine

Understanding the effects of climate change on surface-subsurface hydrology is critical for improving water resources management in a basin. In such cases, the use of hydrological models to quantify and assess water resources is a common practice. With the increasing population and human interventions, the land use changes drastically. The land cover plays a vital role in hydrology as it defines the properties of land surface in the models. So far, majority-of the studies accessing the future climate change consequences on hydrology take into account only the meteorological variables under different climatic projections, neglecting the future land use changes assuming it as static. However, that is not the case, because majority of the earth's surface has altered as a result of human activities, and these changes are represented in models via land use maps.
The study presented herein, aims to assess the surface-subsurface response of the catchment under combined effect of meteorological variables and land use future projection. The analysis is performed on the Aa of Weerijs catchment which is a meso-scale transboundary watershed between Belgium and the Netherlands. The future projections of the meteorological variable were obtained from the Royal Netherlands Meteorological Institute (KNMI-14) website for the Netherlands and the same trends were implemented for the Belgium part of the catchment. For the land use, the European Space Agency (ESA) Climate Change Initiative (CCI) Land Cover (LC) maps of the study area for the year 1992 to 2021 were downloaded and linearly projected for the year 2050. The developed projected map was also compared with projected land use map of year 2050 by LUISA (Land Use-based Integrated Sustainability Assessment) modelling platform.
To investigate the hydrological regime of the area, the fully distributed physically based hydrological model coupled with a hydrodynamic model using MIKE-SHE and MIKE-11 modeling tools was developed. The base model was set up for the year 2009 to 2016. In addition to discharge, the groundwater heads are used to evaluate the model performance.
After setting up the base model, firstly, we analyzed the surface and subsurface response of the catchment considering that the land use in the area is the same as it was in 1992. Secondly, we analyzed the catchment response for the year 2050 by considering the meteorological variables as well as land use future projection.
The study provides unique estimates of future climate change and associated hydrological implications. The findings of the study will be valuable to plan and suggest significant modifications in the current strategies for water management in the area. Moreover, it can contribute to the efficient integration of spatial planning with water management.

How to cite: Ali, M. H., Popescu, I., Jonoski, A., and Solomatine, D.: Climate impact on surface-subsurface hydrology considering meteorological and land use projections., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2627, https://doi.org/10.5194/egusphere-egu23-2627, 2023.

11:20–11:30
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EGU23-8987
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ECS
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On-site presentation
Bob W. Zwartendijk, Ilja van Meerveld, Adriaan J. Teuling, Chandra Ghimire, Hannes Leistert, and Leendert A. Bruijnzeel

Land cover in catchments undergoing shifting cultivation typically represents a mosaic of agricultural fields, fallows in different stages of regrowth, remnant forest, and degraded grasslands. Although runoff responses of the respective land-cover types are expected to differ, there is little quantitative information on how such a mosaic of land covers affects rainfall-runoff responses at the catchment scale.

From February 2015 to February 2016, we measured rainfall, streamflow, plus plot-scale (saturation) overland flow (SOF), soil water, and shallow groundwater dynamics under different land covers in the 31.7 ha Marolaona catchment in Eastern Madagascar. The catchment has undergone shifting agriculture for over 70 years which has resulted in a mosaic of vegetation at different stages of regrowth. Plot-scale hydrological responses varied between land covers and topographic positions, but catchment stormflow responses were generally small and dominated by pre-event water, suggesting that most storm-runoff was generated in the valley-bottom. However, for events exceeding an antecedent soil moisture storage plus rainfall threshold value, stormflow increased considerably, indicating contributions from the hillslopes as well. Despite lower rainfall in 2015/16, stormflow totals and annual water yield were higher than values reported for the driest years in the 1960s[1]. This is thought to reflect a deterioration of soil physical properties by repeated burning, cropping, and associated loss of topsoil during the intervening years, which has reduced the depth to an impeding layer and increases in amount and frequency of SOF.

To gain further insight into the runoff-responses across the catchment, we applied the RoGeR_Dyn model[2] using field-measured soil physical parameters for the respective land covers, topographic data, and climatic inputs. The simulations thus far highlighted greater deep percolation under tree fallows, while SOF was more common during the early stages of regrowth. Amounts of subsurface stormflow and percolation to deeper layers were highest in concave areas where flows converged. Soil moisture contents were lowest under tree-based land covers during the dry season. For nearly the entire dry season, rainfall events supplied the minimum amount of water needed to maintain soil moisture contents above critical levels for transpiration. This agrees with measured soil moisture and tree transpiration rates for nearby sites.

Although the hillslope modelling results are not expected to provide sufficient evidence to determine the effect of land cover on catchment-scale ecosystem services such as streamflow regulation, the lower runoff and higher deep percolation found along hillslopes under older fallows and forest suggest that these may be beneficial for flood mitigation and dry-season water provisioning to downstream areas. Next, RoGeR_Dyn will be used to determine the effects of regional changes in hillslope land cover and climate change on streamflow dynamics.

[1] Bailly, C., et al. (1974). Étude de l'influence du couvert naturel et de ses modifications á Madagascar. Expérimentations en bassins versants élémentaires. Cahiers Scientifiques, 4. Centre Scientifique Forestier Tropical, Nogent-sur-Marne, France, 114 pp.

[2] Steinbrich, A., Leistert, H., Weiler, M. (2021). RoGeR – ein bodenhydrologisches Modell für die Beantwortung  einer Vielzahl hydrologischer Fragen. In Korrespondenz Wasserwirtschaft, 14. Jahrgang, Heft Nr. 2, Feb-2021.  https://doi.org/10.3243/kwe2021.02.004

How to cite: Zwartendijk, B. W., van Meerveld, I., Teuling, A. J., Ghimire, C., Leistert, H., and Bruijnzeel, L. A.: Modelling the hydrological responses of a headwater catchment under shifting cultivation in upland Eastern Madagascar, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8987, https://doi.org/10.5194/egusphere-egu23-8987, 2023.

11:30–11:40
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EGU23-9882
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ECS
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On-site presentation
Ina Sieber, Malte Hinsch, Artur Gil, and Benjamin Burkhard

Modelling and mapping water-related ecosystem services (ES) are getting more important in the scientific community and decision making contexts. Especially straightforward, easy to operate ES model suites that are based on Land Use / Land Cover (LULC) data have gained popularity in the scientific realm, including but not limited to the InVEST Model Suits. Model sensitivity to input factors has been widely assessed. However, little attention has been given to the effect on modelled ES distribution by user decisions such as the selection of LULC dataset. These crucial input data influence model results and hence, validity and credibility of model outputs and maps. Yet, many model applications aim to support policy and decision making, without properly specifying uncertainties of their modelling and underlying data.

Therefore, we investigated how to select appropriate and representative LULC data for model application. To test the effects of input LULC data on modelling results, we modelled the three regulating ecosystem services of water erosion control, water quality and water flow retention using InVEST. Different input LULC datasets were used to analyse how these datasets affect the modelling and mapping of ES supply. Taking a case study on Terceira Island, the Azores (Portugal), 3 LULC datasets were applied: (1) the EU-wide CORINE LULC (2018), (2) the Azores Region official LULC map (COS.A 2018) and (3) a remote sensing-based vegetation map using Sentinel-2 satellite imagery (2018). Output maps were compared by statistical analysis of class for distribution and similarity and visualized in similarity maps, showing the spatial variability between the three input LULC model results.

Model results show significant differences in distribution of water-related ES based on the different input LULCs. For the ES erosion control (Sediment Delivery Module), spatial distribution of modelled output maps differed greatly. Large homogenous agricultural areas in LULC datasets, in combination with steep slopes, present a skewed picture of erosion rates, simplifying the small patch structure with hedges and stone rows found on Terceira island. The modelling of Water quality, based on Nutrient Export Module, and flow retention, based on the Seasonal Water Yield Module, showed a more balanced and similar, yet significantly different spatial pattern of ES supply.

Therefore, we developed a guiding scheme to help researchers and practitioners select appropriate input LULC data for their ES modelling. Hereby, the availability of different LULC data is a first criterion. Factors such as LULC classes, especially linked to aquatic, riparian and agricultural land uses determine the level of detail of water-related ES modelling. Also, the scale of the assessment should be reflected in the average feature size and Minimum Mapping Units of the LULC dataset. Especially for local model applications, availability of high resolution LULC data, including structural elements, is preferred to obtain precise results.

How to cite: Sieber, I., Hinsch, M., Gil, A., and Burkhard, B.: Modelling water-related ecosystem services with InVEST - developing guidance on how to select appropriate land cover input data , EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9882, https://doi.org/10.5194/egusphere-egu23-9882, 2023.

11:40–11:50
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EGU23-11158
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ECS
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On-site presentation
Marcus Buechel, Simon Dadson, Louise Slater, Ségolène Berthou, William Keat, and Huw Lewis

Interest continues to grow in the benefit of afforestation for carbon sequestration, yet the potential consequences of largescale afforestation on terrestrial hydrology are still unknown. Furthermore, it is unclear how large land cover changes may alter the surface-atmosphere hydrological connection, particularly as the climate and hydrological cycle evolve. In this study, we investigate how terrestrial and atmospheric hydrological processes in the UK may alter with increases in woodland across the UK, Ireland, and parts of Western Europe. We use a convection permitting physics-based regional climate model (HadREM3-RA11M) at 2.2 km resolution to simulate and identify the responses of afforestation on hydrology. Afforestation scenarios were generated using existing datasets from regional authorities and previous studies, with tree type determined according to pre-existing landcover. We compare modelled scenarios of widespread afforestation and existing land cover for a future period up to 2080 (with Representative Concentration Pathway 8.5) to assess the consequences of expanded woodland on terrestrial and atmospheric processes within the UK in a much warmer climate.

 

Model results show clear and substantial changes in hydrology in both the atmosphere and land surface with woodland expansion. Soil moisture increases, leading to a commensurate boost to subsurface flows, which is particularly greater in summer months. Although runoff increases throughout the country, there is a proportionally greater increase in the drier south-eastern UK. Evaporation broadly decreases across the country, primarily driven by a reduction in soil evaporation, although this varies seasonally. Precipitation patterns also alter substantially, with increases in the west and slight increases and decreases in the east of the country. These results provide unique insights into how models that couple the land surface with the atmosphere can identify potentially far-reaching consequences of afforestation in temperate regions.

How to cite: Buechel, M., Dadson, S., Slater, L., Berthou, S., Keat, W., and Lewis, H.: High resolution regional climate model points to a wetter UK with widespread afforestation, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11158, https://doi.org/10.5194/egusphere-egu23-11158, 2023.

11:50–12:00
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EGU23-6801
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On-site presentation
Arnout van Soesbergen, Sophia Burke, and Mark Mulligan

ReSET (Restarting Economy in Support of Environment, through Technology) is an EC H2020 research and development project focused on future and emerging technologies (FET) in Environmental Intelligence (EI). EI brings together multiple data streams, employing human reasoning and machine learning to better understand and manage the environment.

As part of ReSET, we are developing and deploying distributed networks of in-field sensors to monitor the hydrological impact of natural flood management, regenerative farming and other ecosystem restoration.  These sensor networks use FreeStation.org, low-cost, internet connected environmental sensing and data logging to provide locally specific evidence for the hydrological impact of a range of restoration investments in different locations and at different scales. More than 100 data loggers  have been deployed for 18 months collecting data every 10 minutes. 

This provides both capacity to directly analyse the effectiveness of investments in water ecosystem services  and co-benefits for non water ecosystem services and helps develop the understanding to better parameterise these restoration investments in spatial models like WaterWorld.  We apply  the WaterWorld Policy Support System  to assess the hydrological impact of novel scenarios for ecosystem restoration at the national and European scale. 

As well as ecosystem restoration, a  key  focus is regenerative agriculture (RA) which is a land management technique that involves no or low tillage, the use of cover crops and diverse crop rotations to help restore soil structure to a more natural state, encouraging infiltration and reducing runoff generation. This management technique has the potential to increase the water storage capacity of the soil, thereby reducing downstream runoff generation and flood risk..

Our local scale monitoring indicates that restoration of Eurasian Beaver habitat and of farmed soil through reduced tillage have the potential to increase flood storage locally and can reduce flood risk at downstream assets if applied at scale. Our national and continental scale modelling indicates that soil and canopy stores are critical to natural flood management since water body and wetland stores have only local influence and floodplain stores often contain important assets that preclude the use of the floodplain.  Ecosystem restoration has the potential to regenerate Europe's waters, but significant effort will be required to reach the level of restoration that will be needed 

How to cite: van Soesbergen, A., Burke, S., and Mulligan, M.: H2020ReSET: Monitoring and modelling the hydrological impact of ecosystem restoration scenarios at scales from local to continental using FreeStation and WaterWorld, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6801, https://doi.org/10.5194/egusphere-egu23-6801, 2023.

12:00–12:10
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EGU23-3393
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ECS
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On-site presentation
Iporã Possantti, Rafael Barbedo, Marcelo Kronbauer, Walter Collischonn, and Guilherme Marques

Hydrological models are crucial tools in planning the restoration of water-related ecosystem services because they help target priority areas for efficient resource allocation. However, when planning the expansion of Nature-based Solutions and Payments for Ecosystem Services, there are four key requirements that need to be taken into account. These are (1) the principle of additionality, which states that restoration policies must seek additional gains in terms of ecosystem services; (2) the representation of multiple runoff mechanisms, which can be fundamentally different in nature; (3) the calculation of farm-scale spatial outputs, which allows for the examination of the impacts of management practices at the level of individual farms; and (4) the estimation of epistemic uncertainty, which is the uncertainty that arises due to a lack of knowledge and information.

While addressing these requirements is important for making future planning more effective it can also be challenging. To address this challenge, this paper presents a comprehensive modeling framework that integrates these requirements in a way that allows for an improved selection of top priority areas with farm-scale spatial resolution, and a deeper understanding of how epistemic modeling uncertainty affects the results. This is particularly important when it comes to evaluating the risks of overestimating water-related ecosystem services benefits.

The modeling approach that we propose, called PLANS, uses the design of TOPMODEL to simulate both saturation-excess and infiltration-excess runoff at the farm-scale resolution. It also employs a novel saturation index based on a combination of the Height Above the Nearest Drainage (HAND) and Topographical Wetness Index (TWI) terrain descriptors. To estimate output epistemic uncertainty, we apply the Generalized Likelihood Uncertainty Estimation (GLUE) method, aided by an evolutionary algorithm. We demonstrate the effectiveness of the PLANS model in a case study watershed in the Atlantic Forest biome of Brazil. Our results show that uncertainty can significantly impact the definition of priorities, with a 97% ranking change. We also find that simulated topographic effects can outweigh local effects of land cover and soil type. By better evaluating uncertainty, we demonstrate that the cost of the restoration program in the study case could potentially be reduced by up to 27%, making it more cost-effective.

Overall, our modeling approach offers a promising way to address the challenges of planning the expansion of Nature-Based Solutions in watersheds and deploying programs of Payments for Ecosystem Services. It allows for the improved selection of top priority areas and a deeper understanding of the impacts of epistemic uncertainty on the outputs. By taking these considerations into account, society can make more informed decisions about how to allocate resources and design restoration programs that are both effective and efficient.

How to cite: Possantti, I., Barbedo, R., Kronbauer, M., Collischonn, W., and Marques, G.: Modeling priority areas for restoration of water-related ecosystem services under epistemic uncertainty: a case study in the Atlantic Forest, Brazil, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3393, https://doi.org/10.5194/egusphere-egu23-3393, 2023.

12:10–12:20
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EGU23-6035
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ECS
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On-site presentation
Kalina Fonseca, Miguel Ramírez, William Martínez, Edgar Espitia, and Lutz Breuer

The limited spatial scope of Andean basins conservation agreements by nature-based solutions (NbS) in the tropical alpine grassland region (páramos) has led to unequal protection of upstream ecosystems, endangering the water quality downstream of large Andean cities. Simultaneously, the páramos have been converted to other land uses in response to the political, economic, social, technological, ecological, and legal (PESTEL) factors. In this context, we aim to compare the negative impacts associated with land use/land cover (LULC) change and the positive effects of nature-based solutions in the upper Andean basins using remote sensing data, PESTEL analysis, and water quality assessment. The upper basin of the Pita and Cutuchi rivers, located above 3,000 m.a.s.l., which supply drinking and irrigation water to two major Andean cities in Ecuador, i.e., Quito (the capital of Ecuador) and Latacunga (an important city for floriculture and agriculture), were examined in comparison as case studies between 1999 and 2022. Our results reveal significant land-use changes from páramo to agriculture, Pinus plantations, urban growth, and mining areas in the upper basin of the Cutuchi river, driving water quality between low to moderate for drinking and irrigation purposes. According to the PESTEL framework, the main factors contributing to the lack of upper basin protection are (1) short-term policies in line with the political party, (2) state budget planning that does not meet restoration needs, (3) conflicts between the upper, middle, and lower river basin communities, (4) lack of public investment in technological tools, (5) agricultural practices in the páramo due to high soil carbon storage in comparison to other areas and (6) conflicting laws between administrative divisions. In contrast, main páramo areas have remained unaltered or passively restored in the upper basin of the Pita river by the combination of NbS and policies implemented by water funds, conserving good water quality. By using these catchments as ideal natural laboratories, we can demonstrate the positive experiences through NbS in river basin management. Together with our PESTEL analyses, it is possible to develop integral conservation projects that ensure human health and sustainable agricultural productivity in the context of Sustainable Development Goal (SDG) 6: Clean Water and Sanitation.

How to cite: Fonseca, K., Ramírez, M., Martínez, W., Espitia, E., and Breuer, L.: Assessing the impacts of land use/land cover (LULC) change and the effects of nature-based solutions in Andean basins., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6035, https://doi.org/10.5194/egusphere-egu23-6035, 2023.

12:20–12:30
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EGU23-14983
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On-site presentation
Maria J. Santos, John C. O'Connor, Kien Nguyen, Obbe Tuinenburg, and Stefan C. Dekker

Land use changes can affect many dimensions of the hydrological cycle which in turn affect the provisioning of water and its related ecosystem services to society. Modification at different spatial and temporal extents due to seasonal changes in water supply and land use intensities may compound and challenge our ability to predict the cascade of processes that lead to the supply of ecosystem services, i.e., ecosystem service cascade (ecosystem property, supply and service). In the Amazon basin, land use changes may affect water supply through modification of moisture recycling periodicity, and a quantification of its effects on other water-related ecosystem services, namely crop production and biodiversity, is scarce. We investigated this process using a moisture-tracking model, to show that upstream land use changes will affect the persistence of cropland in the Amazon arch of deforestation.  We also show that biodiversity trait distributions affect the provision of water that maintains the cascades of moisture recycling, and different trait combinations enable regulation of atmospheric water regulation and land surface temperature. As trait combinations are a result of land use changes, the future of moisture recycling in the Amazon and its dependence downstream may require a better land use planning that incorporates these processes more explicitly.

How to cite: Santos, M. J., O'Connor, J. C., Nguyen, K., Tuinenburg, O., and Dekker, S. C.: Effects of land use change on water-related ecosystem services in the Amazon Basin, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14983, https://doi.org/10.5194/egusphere-egu23-14983, 2023.

Posters on site: Wed, 26 Apr, 16:15–18:00 | Hall A

Chairpersons: Giulio Castelli, Sofie te Wierik, Tommaso Pacetti
A.104
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EGU23-3142
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ECS
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Safae Aala, Stefano Basso, Dietrich Borchardt, Thomas Hoffmann, and Soohyun Yang

Investigating the influence of land-cover mosaics on water quality is vital for effective management aimed at mitigating the hazard of exceeding regulatory water quality thresholds. In particular, suspended sediments in rivers can easily jeopardize aquatic ecological functions, by transporting significant amounts of pollutants along flow paths. Nonetheless, a relationship between land-cover mosaics and suspended sediment dynamics remains unclear due to the complexity of interactions and feedbacks between geomorphological and hydrometeorological conditions in diverse river basins. Here, we aim to analyse the linkages of landscape metrics describing the spatial patterns of land-cover with the (power-law) rating exponent of suspended sediment concentration SSC and river discharge Q (i.e. SSC = aQb), as an integral property of sediment dynamics. For three major river basins in Germany (Elbe, Rhine, and Weser covering about 66 % of total German territory), the sediment rating parameters are extracted at high flows. Moreover, thoroughly selected descriptors are computed to characterize the composition and spatial configuration of land cover as well as topographic and hydrogeological conditions (e.g., temporal variability in Q and flashiness index). Preliminary results show the existence of correlations between the spatial organization of land cover along the river network and the rating exponent b at high flow regime. In particular, they indicate that high increase in suspended sediments at high flows is generated in catchments with more homogeneous land cover and sediment sources distributed near large streams. Our findings can aid policymakers and watershed managers in making informed decisions and taking necessary actions to improve current and future river water quality issues caused by suspended sediments.

How to cite: Aala, S., Basso, S., Borchardt, D., Hoffmann, T., and Yang, S.: Do land-cover mosaics affect the variability of suspended sediments in rivers? The case of large river basins in Germany, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3142, https://doi.org/10.5194/egusphere-egu23-3142, 2023.

A.105
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EGU23-705
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ECS
Esraa Tarawneh, Jonathan Bridge, and Neil Macdonald

Sedimentation is a major issue at the Wala Dam, Jordan, and its impact on the serviceable lifetime of the reservoir is the primary driver for proposals to raise the height of the dam. The approach followed in this study involves the application of an optimized SWAT model of the Wala catchment to examine hypothetical and object-based catchment management scenarios, including land-use alteration, on a one-at-a-time basis to simulate discharge and sediment yield delivered to the dam over the period 1979 – 2013. Plantation scenarios study the response of the catchment to cultivation of barley and olive in selected areas. The simulated effect of altering plantation vary spatially with both location and scale. Changes in annual sediment and water delivery to the Wala reservoir are linked to a simple model of dam functional lifetime to establish a rational model framework for integrating hydrological and ecological decision-making in this highly-stressed setting. Considering the Wala Dam raising plan, it is concluded that the current capacity is hypothetically expected to fill up with sediment in 65.63 years based on the existing land-use conditions of the catchment. The ongoing 17 Mm3 expansion of the dam is predicted to lengthen life-span up to about 283 % of the current estimations based on the existing land-use. Longest life-span of the Wala Dam is expected to be achieved by cultivating the northern areas with olive in all cases considereing exisiting and expanded capacity within extreme and average climate conditons. Shortest life-span is relevant to cultivating barley over the whole catchment. Life-span estimated based on an extreme flood condition that occurred in year 1992 varies between 2.92 and 10.02 year. Although such conditions can be rare and highly unpredictable, they must be taken into consideration while designing dams. Land-use alteration plans do not necessarily improve life-span of the dam and therefore, careful studies must investigate end goals and feasibility of management plans. Catchment-scale water and sediment management within the Wala basin is part of a complex system of inter-relationships within the overall framework of the water-energy-food nexus. Retention of water in the landscape for ecological benefit, to the detriment of available resource to support water supplies, carries a significant cost in this context; on the other hand, the model results here suggest that land restoration (at least under the cropping scenarios tested) can be achieved with marginal impacts relative to the benefits of raising the Wala dam. This, however, has its own consequence; by further eroding the downstream export of water to the Dead Sea, schemes such as the Wala contribute to the progressive deterioration of that unique water body, with impacts of global ecological, cultural, economic and geopolitical scale. The variation observed between simulated land-use scenarios emphasises the potential use of catchment modelling to target land restoration measures to those areas where net ecological benefits, including water conservation and reduction of erosion, are maximised.

How to cite: Tarawneh, E., Bridge, J., and Macdonald, N.: Implications of land-use alteration on discharge and sediment delivery using hydrological modelling , EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-705, https://doi.org/10.5194/egusphere-egu23-705, 2023.

A.106
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EGU23-2041
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ECS
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Gabriel Stecher, Severin Hohensinner, and Mathew Herrnegger

Long-term land use and land cover changes (LULCC) are estimated to affect almost one third of the global land area (Winkler et al., 2021). This also alters hydrological processes and has implications on the ability of the landscape to retain water. In alpine areas of Austria, extensive LULCC have occurred since the mid-19th century, which also led to changes in flood hazard and an increase in flood risk, especially in the valley floors.

This contribution analyses, how long-term LULCC from the 1820s until now affect the water retention potential of the Austrian catchments of the rivers Rhine, Salzach and Drava. The Water retention index (WRI) (Vandecasteele et al., 2017) was calculated at a high spatial resolution (100*100 m) for the past and present LULC situation. The WRI is a qualitative indicator and shows the water retention capacity on a relative scale (0-10) by a composition of the governing physical processes (e.g. interception, percolation) through proxy datasets.

The resulting WRI maps of the historic and present state reveal that the general spatial features and characteristics exhibit similar WRI patterns. High values (WRI > 5) occur in valley floors and rather flat areas. Areas dominated by steep topography and alpine characteristics show low WRI values (< 3). The comparison of the two time periods shows a moderate to strong reduction (< -2) of the water retention potential especially in the alpine valleys and low elevations for the current state. This is largely explained by the expansion and development of settlement areas and soil sealing. Additionally, the draining of wetlands, river channelization and disconnection of flood plains and deforestation also strongly reduced the WRI values. In contrast, increasing WRI values occur primarily in areas at higher altitudes. Here, forest areas increased and wasteland transformed to grassland. In addition, new artificial water reservoirs have been constructed to produce hydropower, which have a positive effect on the retention potential. Generally, the spatial and altitudinal changes in the water retention capacity reflects the land and settlement development in the past 150 years. This development resulted in higher flood exposure but might have also reduced flood hazards due to higher water retention capacities.

References:

Vandecasteele, I., Marí i Rivero, I., Baranzelli, C., Becker, W., Dreoni, I., Lavalle, C., and Batelaan, O., 2017. The Water Retention Index: Using land use planning to manage water resources in Europe. Sustainable Development, 26 (2), 122–131. https://doi.org/10.1002/sd.1723

Winkler, K., Fuchs, R., Rounsevell, M., and Herold, M., 2021. Global land use changes are four times greater than previously estimated. Nature Communications, 12 (1), 1–10. https://doi.org/10.1038/s41467-021-22702-2

How to cite: Stecher, G., Hohensinner, S., and Herrnegger, M.: How land use and land cover change affect the water retention of alpine landscapes in Austria, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2041, https://doi.org/10.5194/egusphere-egu23-2041, 2023.

A.107
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EGU23-1197
|
ECS
Wei-Cheng Chin and Chihhao Fan

    This study used two hydrological models and three economic valuation models to evaluate the ecosystem services of three selected upper river catchment areas of Taiwan and compares the differences among the comprehensive ecosystem service values among them. The differences in the evaluation results could be the basis for developing the related national river catchment management policies. The hydrological balance and Thiessen polygons methods were used to assess soil water conservation in the investigated areas. The replacement cost, market price and surrogate market methods were employed to estimate the supplying, regulating, supporting and cultural service values.

     Based on the survey of the public’s preference for ecosystem services conducted by the Council of Agriculture, Taiwan in 2020, the value of each individual ecosystem service is weighted and added together to represent the comprehensive ecosystem service values. The rank of the comprehensive ecosystem service values of the the three investigated catchment areas from high to low is the Dahan river in northern Taiwan, Dajia river in central Taiwan, and the Zengwen river in southern Taiwan.

    In this study, we analyzed the calculated results and suggested possible future policy for three investigated rivers, helping to allocate limited resources to achieve best cost-effect results. According to the present study, the ecosystem service values of flood control and landslide prevention are the two most-valued indicators. However, these two service values estimated by replacement cost method was significantly higher for the Dahan river than the Dajia river and Zengwen river. In order to enhance the comprehensive ecosystem services and balance for the regional economic development, government policies should aim to increase the ecosystem service values of flood control and landslide prevention in the upper catchment areas of rivers for central and southern Taiwan.

How to cite: Chin, W.-C. and Fan, C.: Ecosystem Services Assessment in the Upper Catchment of Taiwan River Basins, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1197, https://doi.org/10.5194/egusphere-egu23-1197, 2023.

A.108
|
EGU23-5142
|
ECS
Mohamed Aboelnour, Jennifer Tank, Alan Hamlet, Leonardo Bertassello, Dongyang Ren, and Diogo Bolster

High nutrient loads are an indicator of pollution sources in a watershed that need to be identified and quantified. These loads in surface and groundwater have been a major concern that impacts water quality in the Midwestern US, including the Great Lakes Basin. To investigate the influence of land use change, especially at urban/rural interfaces, we used the Soil and Water Assessment Tool (SWAT) to model water, sediment, and nutrient export for the St. Joseph River Basin (SJRB), which drains an area of 12,200 km2 in Southwest Michigan/Northwest Indiana and enters Lake Michigan. The SWAT models were built, calibrated and validated for monthly streamflow, groundwater, total suspended solids (TSS), total nitrogen (TN), total phosphorous (TP), nitrate (NO3-N) and dissolved reactive phosphate (DRP; as orthophosphate), using two stream gages (Niles, USGS ID 04101500; Paw Paw, USGS ID 04102500) in Berrien County, MI. We found that monthly hydrology, sediments, and inorganic nutrients were well captured by the model with very good to excellent performance at the Niles gage, and, good to satisfactory performance at Paw Paw. The simulated average annual groundwater was 137 mm and 129 mm for Niles and Paw Paw, respectively, suggesting that on average 57% and 60% of long-term streamflow in the basin comes from groundwater and shallow subsurface flow. For water quality variables, TSS loads were strongly correlated with streamflow with R2 reaching 0.90. Using this model, we investigated how land use change (e.g., agriculture), and the planting of winter cover crops in the fallow season would impact water and nutrient yields from the SJRB. We found that the impact of changing land use and applying cover crops on water quality components was significant and dependent on the selected spatial scale. The simulated outputs indicated that cover crops have no impact on hydrology but significantly reduced DRP and NO3-N export to Lake Michigan by up to 30% and 50%, respectively. Application of this model will assist regional land and water managers in planning for future impacts of land use and climate change and their impacts on water quality and quantity, enabling stakeholders to implement conservation practices to sustain the SJRB and other similar basins in the Great Lakes region.

How to cite: Aboelnour, M., Tank, J., Hamlet, A., Bertassello, L., Ren, D., and Bolster, D.: Modeling the Impact of Changing Land Use and Vegetative Cover on Hydrology, Nutrient, and Sediment Loads from an Agricultural Catchment of Lake Michigan (USA), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5142, https://doi.org/10.5194/egusphere-egu23-5142, 2023.

A.109
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EGU23-2115
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ECS
|
Merav Tal-maon, Dani Broitman, Michelle Portman, and Mashor Housh

Water management has recently changed from relying purely on technical and engineering methods towards nature-based solutions. These solutions can potentially benefit beyond hydrological concerns, such as improving life quality and biodiversity conservation. These measures are referred to as Natural Water Retention Measures (NWRM) in the water sector. Identifying the optimal type and locations of these measures is challenging due to the abundance of possible solutions, with different potential benefits and varying effects, depending on the characteristics of each place. Most research into sustainable runoff management addresses quantity, quality, and economic issues; few studies link these considerations with environmental and social benefits. We propose a methodology for identifying the most effective areas to place NWRMs and offer criteria for selecting appropriate measures based on hydrological, ecological, and social benefits.

To simulate the effect of NWRM, we applied the Open Nonpoint Source (NPS) Pollution and Erosion Comparison Tool (OpenNSPECT) to simulate the hydrological processes in the Tavor basin. We ran the model multiple times; each time, we simulated increased infiltration in a different land parcel and used the resulting change in runoff, sediment, and pollutants to construct a Pareto frontier graph. We then identified a set of appropriate measures for each area using information from the EU Directorate General for the Environment to conduct a cost-benefit analysis of different water retention measures. Different measures were selected when considering social and ecological benefits than only hydrological benefits, further highlighting the importance of accounting for these aspects. This methodology, which links hydrological concerns with the less commonly found ecological and social aspects, could serve as a decision-making tool for planners and stakeholders with sustainable runoff management.

How to cite: Tal-maon, M., Broitman, D., Portman, M., and Housh, M.: Identifying optimal type and locations of natural water retention measures using spatial modeling and cost-benefit analysis, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2115, https://doi.org/10.5194/egusphere-egu23-2115, 2023.

A.110
|
EGU23-16583
|
ECS
Sofie te Wierik, Jessica Keune, Diego Miralles, Erik Cammeraat, Joyeeta Gupta, Yael Artzy, and Emiel van Loon

The redistribution of biological (transpiration) and non-biological (interception loss, soil evaporation) fluxes of terrestrial evaporation via atmospheric circulation and precipitation is an important Earth system process. Overall, vegetation is the main contributor to terrestrial evaporation and subsequent precipitation over land. Yet, the specific contribution of different vegetation classes remains understudied. Here, we investigate how different vegetation classes (trees and non-tree vegetation) contribute to precipitation patterns through moisture recycling over African watersheds. Our study is based on simulated daily atmospheric moisture trajectories derived from the Lagrangian model FLEXPART, driven by 1° resolution reanalysis data over 1981–2019, aggregated at the monthly level. The data is constrained by evaporation and precipitation products, and unravels the annual and seasonal contribution from trees and non-tree vegetation to precipitation, employing fractional vegetation cover data. Our findings show that trees provide a higher water flux to precipitation over Africa compared to non-tree cover, with contributions of 777 mm year-1 versus  342 mm year-1  respectively. However, the large extent of non-tree vegetation over the continent compensates for this difference and many watersheds depend even largely on non-tree vegetation for precipitation. As non-tree vegetation appears to be important for precipitation over Africa, its current contribution to water availability should not be overlooked and requires further research, particularly in relation to ongoing land use and land cover change that may affect hydrology. Providing an outlook on existing and projected land use and land cover change, we highlight the spatial heterogeneous impact on local and regional water availability over the continent.

How to cite: te Wierik, S., Keune, J., Miralles, D., Cammeraat, E., Gupta, J., Artzy, Y., and van Loon, E.: Revealing the importance of transpiration from trees and non-tree vegetation to moisture recycling over Africa, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-16583, https://doi.org/10.5194/egusphere-egu23-16583, 2023.

A.111
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EGU23-15446
|
ECS
Marco Lompi, Tommaso Pacetti, Giovanni Pasini, and Riccardo Santolini

Forest management can represent a powerful tool to optimise ecosystem services related to water, as water availability is deeply connected with forests and their management. The objective of this study is to improve the understanding of the forest–water connection, developing a methodology that can explain which forest types and management strategies can increase water availability and flood protection in Casentino Forest National Park (Parco Nazionale delle Foreste Casentinesi). The different forest management types for every species considered in the study are abandoned or unmanaged forest, coppice, coetaneous and non-coetaneous high forest. The Casentino Forest National Park in Central Italy on the Apennine Mountains covers a set of 25 small river basins, which have been chosen as a case study to test a methodology based on hydrological modelling and machine learning tool. First, the Soil Water Assessment Tool (SWAT) has been calibrated and used to model the baseline scenario, evaluating the ecosystem services the forest park provides. The baseline scenario has been built in the SWAT model, characterising the forest-related parameters, such as the leaf area index, the leaf-to-biomass fraction, the biomass of the forest or the canopy storage among others. This information has been retrieved with land use data, such as the Corine Land Cover, available forest technical map and MODIS satellite images. The following step has been the analysis of multiple land use scenarios to understand the potential effect of different forest management on water-related ecosystem services. Nevertheless, the SWAT model is hugely time-consuming in modelling several land use scenarios, as each forest management strategy needs to be described with a new set of parameters and model runs. For this reason, a Support Vector Machine (SVM) learning model has been trained to reproduce the hydrological behaviour of the Park using the  SWAT model outputs for the baseline scenario as a training dataset. The SVM has been validated with a Jack-Knife cross-validation to test its reliability in determining the average annual water yield, runoff, evapotranspiration and percolation in the river basins using the different forest management types as input. Then, the SVM has been used to model a set of 4200 different land use scenarios to understand the type of forest with the higher water yield content or lower surface runoff. The results show that the oldest forests, especially with a prevalence of oaks, have great potential in regulating services, while the coppices contribute more to the provisioning services.

How to cite: Lompi, M., Pacetti, T., Pasini, G., and Santolini, R.: Forest management strategies to improve water-related ecosystem services in central Italy, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15446, https://doi.org/10.5194/egusphere-egu23-15446, 2023.

A.112
|
EGU23-7192
|
ECS
Sonam Sandeep Dash, Bidroha Basu, Fiachra O'Loughlin, and Michael Bruen

Population growth in conjunction with rapid urbanization and industrialization has put immense pressure on global land use and land cover (LULC) patterns, and subsequently, adversely affect the water quantity and quality of associated water resources. The involved rate of change, spatio-temporal distribution of altered LULC classes, and the corresponding trend of LULC classes are quite challenging to monitor by using the conventional field survey-based approach. This study aims to analyse the changes in urbanization extent over Ireland during the past two decades, i.e., 2001-2021 using remotely sensed imageries. In addition, the extent of urbanization and its association with population growth is studied in detail over 43 spatially distributed study catchments of Ireland. One advantage of using remotely sensed LANDSAT observations include high-resolution spatial data available at a high temporal scale and also that the imagery is available for such long period covering the entire study period. The urbanization mapping is confined to two meteorological seasons, viz., summer and winter of every year analyzed. To aid more reliability in the outcomes of this study, the ACOLITE-based atmospheric correction algorithm has been adopted and the imageries were pre-processed before performing the image classification. The urbanisation trend over the period 2001-2021 revealed that the urban area expansion across the chosen catchments has happened at a rate of 0.13 to 1.14 km2/yr with the highest urban expansion rate is confined to the Dublin region of Ireland during the summer season. Furthermore, a correlation-based approach has been extended to study the drivers of increased urbanization in Ireland. The outcome of the correlation analysis revealed that population growth is the major driver behind increased urbanization and does affect the water resource quality adversely. The developed approach could be well replicated at any global catchment/regional-scale applications to generate essential database and analyse its impact on the water resources of the region of interest.

How to cite: Dash, S. S., Basu, B., O'Loughlin, F., and Bruen, M.: Identification of extent and drivers of urbanisation in Ireland: A remote sensing-based approach, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7192, https://doi.org/10.5194/egusphere-egu23-7192, 2023.

A.113
|
EGU23-11424
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ECS
|
Dhritilekha Deka, Karangat Ravi, and Archana M Nair

Urbanisation induced land use land cover changes (LULC) are irreversible and is an intensifying worldwide phenomenon. The unprecedented urban growth rate affects the hydrological system and its associated ecosystem services. This has led to a situation where even regions with huge water potential such as the Ganga-Brahmaputra basins of India, are experiencing potable water scarce conditions. Hence, this study is an effort to evaluate the role of LULC on the groundwater resources of Kamrup district, along the banks of River Brahmaputra in Assam. The study entails a quantitative analysis using GIS applications, whereas the statistical significance is evaluated using Man Kendall trend analysis. Satellite images of Landsat and Sentinel are clustered and segmented to classify six different classes. The cloud-based platform of Google Earth Engine (GEE) is utilised for the object oriented (OO) classification. A combination of Simple Non-Iterative Clustering (SNIC) and Random Forest Classifier is utilised to obtain an accuracy >85% for all the images. It is observed that the area under agriculture and wetlands has reduced by 58.99% and 44.7% between 1990 to 2020, respectively. On the other hand, the area under urban impervious cover has increased from 1.875% in 1990 to 17.05% in 2020. The Mann Kendall trend analysis of the groundwater levels shows that 69% of the well locations demonstrate a declining trend at 95% confidence interval. The maximum decline rate is of 0.13 m year−1 and minimum decline rate is 0.03 m year−1. Comparative investigation of the groundwater decline and urban growth shows that 47% of the groundwater wells with declining water levels are located in regions urbanised from 1990 to 2020. The decline in the groundwater levels can be attributed to increased impervious surfaces with the urbanisation. Further, the reduced chances of infiltration have led to amplified runoff and floods with reduced groundwater level in the wells. The results from this study indicate that the depletion in groundwater across the study area can be strongly linked to anthropogenic interferences. Such monitoring of LULC changes along with the dynamics in water levels across the study area, provide a necessary database for the protection, decision-making and sustainable management of the existing freshwater resources.

How to cite: Deka, D., Ravi, K., and Nair, A. M.: Assessment of land use land cover changes and its impact on groundwater resources of Kamrup along the banks of the River Brahmaputra, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11424, https://doi.org/10.5194/egusphere-egu23-11424, 2023.

A.114
|
EGU23-12042
|
ECS
Hojun Choi, Kihwan Song, and Jinhyung Chon

As a transition zone between the aquatic and terrestrial ecosystems in river basins, riparian buffers are important for providing ecosystem services such as water quality purification and biodiversity improvement.

The existing dam basin areas have a problem of weakening or decreasing ecosystem resilience due to damage and disturbance such as non-point pollution sources. Therefore, a suitable site must be selected to create a riparian buffer zone around the area where damage and disturbance occur.

However, the previous studies have limitations in that they do not consider socio-ecological characteristics and the changes that depend on various factors, such as approaches of various spatial scales, structural and institutional support, and physical conditions for each site.

Therefore, the purpose of this study is to derive the final suitable site for a riparian buffer zone in a target site through the quantitative establishment of appropriate site selection indicators that take into consideration the social and environmental factors necessary for the establishment of a riparian buffer zone in a dam basin and the overlapping of established indicator data.

The Han River is the largest in Korea with the largest basin area and its major water resource facilities are distributed. In this study, a suitable site analysis was performed for the Chungju Dam and the Soyanggang Dam among the Han River water systems.

First, the items necessary for field analysis were derived based on a literature review. As a result, the indicators related to geographical conditions, soil environment, water quality environment, environmental ecology, and legal conditions were derived.

Second, data were constructed based on the digital elevation model, land cover map, water quality measurement network, and national environmental assessment map for the selected indicators. As a result, 21 different types of maps were derived according to geographical conditions, soil environment, water quality environment, environmental ecology, and legal standards.

Third, 21 data previously established by type were overlapped and prioritized to determine the appropriate locations for the Chungju Dam and the Soyanggang Dam. The Chungju Dam and Soyanggang Dam areas were ranked in the top 20 per cent among 106 and 42 zones, respectively. Finally, eight fields were derived for each dam through consultations and discussions with related organizations.

This study is meaningful in that it derived suitable items of analysis by considering various socio-ecological and legislative factors and selected suitable sites according to the priorities that were graded based on them. The process of this study can be applied to other studies for the creation of riparian buffer zones in the future.

Acknowledgement

This research was supported by "Development of living shoreline technology based on blue carbon science toward climate change adaptation" of Korea Institute of Marine Science & Technology Promotion (KIMST) funded by the Ministry of Oceans and Fisheries (KIMST-20220526). Also This research is a part of Environmental Fundamental Data Examination project of River Hangang Basin Management Committee

 

 

How to cite: Choi, H., Song, K., and Chon, J.: Suitable Site Selection for Riparian Buffer Zone Construction in the Han River Basin, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12042, https://doi.org/10.5194/egusphere-egu23-12042, 2023.

Posters virtual: Wed, 26 Apr, 16:15–18:00 | vHall HS

Chairpersons: Giulio Castelli, Sofie te Wierik, Tommaso Pacetti
vHS.15
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EGU23-7075
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ECS
|
Jana Balzer, Sally Janzen, Fabian Merk, and Yvonne Walz

Floods are amongst the most frequent and widespread disaster worldwide, posing enormous development challenges. Also in West Africa, flood risk still needs proper addressing. Ecosystem-based disaster risk reduction (Eco-DRR) approaches are increasingly recognised as cost-effective part of the solution, providing ecosystem services that reduce all three components of risk, namely hazard, exposure and vulnerability. Indeed, Eco-DRR, such as floodplain restoration or agroforestry, can affect hydrological processes, altering the flood hazard and exposure, and provide ecosystem services that reduce people’s vulnerability to floods and/or enhance their adaptive capacities. To fully understand the impact of Eco-DRR on the three components of risk, it is thus important to take an interdisciplinary approach to the assessment of Eco-DRR. Yet, there remains a substantial gap in the comprehensive evaluation of Eco-DRR effects, including guidance on how to depict the flow of ecosystem services and their benefits to people, which undermines the effective use of Eco-DRR measures in flood-prone environments.

Using the case study of flood risk in the Ouémé River Basin, this contribution will share advances in the comprehensive evaluation of Eco-DRR measures. After defining locally-relevant Eco-DRR measures based on administrative plans, the scientific literature, and expert surveys, a systematic literature review has been conducted to understand the impact of selected Eco-DRR measures on both hydrological processes and ecosystem services provisioning, so as to evaluate the Eco-DRR measure against its effects on all risk dimensions. For the hazard, the hydrological model SWAT is used, comparing the flood hazard under different land use and land cover change scenarios. Preliminary results, with a focus on the Eco-DRR measure of agroforestry, and lessons learnt will be presented in the session.

How to cite: Balzer, J., Janzen, S., Merk, F., and Walz, Y.: Ecosystem-based approaches for flood risk reduction: Advances in their comprehensive evaluation using the case of the Ouémé River Basin in Benin, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7075, https://doi.org/10.5194/egusphere-egu23-7075, 2023.

vHS.16
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EGU23-12098
|
ECS
|
Triveni Majhi and Meenu Ramadas

Implementation of best management practices (BMPs) is essential for conservation of soil and water resources, and for preventing degradation of water related ecosystem services (WES) in agricultural watersheds. Assessment of effectiveness of BMPs to mitigate problems due to erosion and peak runoff at watershed scale can be performed through scenario analyses in hydrological models such as Soil and Water Assessment Tool (SWAT). In this study, we performed spatial assessment of vulnerability of a small watershed (Jambhira) located in eastern part of India to erosion and sediment loading, in order to evaluate the effectiveness of few BMPs to mitigate the negative impacts of erosion. We utilized the SWAT model to simulate watershed management options such as grassed waterways, terracing, filter strips, strip contour cropping and stream bank stabilization as BMPs. After identifying critical soil erosion prone areas in the study watershed, BMPs are implemented targeting a decrease in sediment output, minimizing loss of nutrients, and lowering of peak runoff from the watershed. In a similar manner, critical reach sections are also determined for implementing suitable BMPs. Out of 21 sub basins of the study watershed, 14 sub basins fall under category of “very high” soil erosion (sediment yield is 20-40 t/ha/yr) and among these 14 sub basins, the reach corresponding to 6 sub basins have a significant sediment concentration. Thus, BMPs are implemented in the six critically soil erosion prone sub basins that constitute 34.29% of watershed area. Based on the geography and land use of the study watershed, we found the land management operations: contour farming and strip contour cropping, and channel restoration strategies: buffer strips and grassed waterways, as most suitable. After implementation of contour farming and strip contour cropping, it is seen that the critical sub basins have moved from “very high” to “high” and “moderate” soil erosion categories thus leading to improved WES in the area. Based on simulated results, the effectiveness of strip contour cropping is found to be higher than contour farming in reducing sediment yield of the study watershed. With additional interventions proposed for reach management in this watershed, it is possible to reduce negative effects of erosion substantially.

Key words: Best Management Practices, Soil Erosion, Soil and Water Assessment Tool, Watershed Conservation, Sediment Yield

How to cite: Majhi, T. and Ramadas, M.: Evaluation of Best Management Practices (BMPs) For WES Conservation in an Agricultural Watershed, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12098, https://doi.org/10.5194/egusphere-egu23-12098, 2023.

vHS.17
|
EGU23-14603
|
ECS
Sukhsehaj Kaur and Sagar Chavan

The hydrology of a catchment is sensitive to its intrinsic attributes, such as the land use/land cover
(LULC), soil type, and topography, which collectively determines its response to the weather inputs
(e.g., precipitation, temperature, radiation, etc.). The dynamic nature of LULC in both space and time
poses a severe challenge in the reliable prediction of the hydrologic response of catchments.
However, the spatio-temporal variation in LULC is seldom accounted for in hydrological modeling
studies, which leads to an inaccurate characterization of the watershed. In this study, we have
incorporated dynamic LULC (both in space and time) within the Soil and Water Assessment Tool
(SWAT) model, using SWAT-LUT (Land use Update Tool) for the Nowrangpur catchment in India. The
LULC maps corresponding to the years 1985, 1995, 2005, and 2015 are used to generate the
intermediate years’ maps via linear interpolation. The future LULC maps till the year 2035 are
predicted using Cellular Automata- Artificial Neural Network (CA-ANN) algorithm in the GIS
framework. It is observed that there is a reduction in the forest cover from 19.13% in the year 1985
to 7.55% in the year 2015, along with the expansion of urban areas and impervious surface from
0.36% in the year 1985 to 2.47% in the year 2015. Calibration and validation of the monthly
streamflows are performed by accounting for dynamic LULC within the catchment through SWAT-
LUT. The satisfactory performance of the SWAT model is observed in predicting the monthly
streamflows in the Nowrangpur catchment. Further, the comparison of streamflow prediction under
static and dynamic LULC is performed. In these two cases, the observed changes in the values of
water balance components (i.e., with and without using SWAT-LUT), such as evapotranspiration,
surface runoff, infiltration, and water yield, are studied. The changes in the water balance
components are attributed to the LULC changes within the catchment. The results indicate that the
land use update (to account for the Spatio-temporal variability in LULC) needs to be incorporated to
determine the reliable hydrological response of a catchment.

How to cite: Kaur, S. and Chavan, S.: Assessing impacts of Spatio-temporal changes in land use and land cover on the hydrologic response of an Indian Catchment, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14603, https://doi.org/10.5194/egusphere-egu23-14603, 2023.